Leaky signals from badly-installed AT&T U-Verse systems are squeezing up into the cable network and degrading broadband performance for others on some nodes, according to Comcast. About 40 cases of the problem have been reported since AT&T began supplying U-Verse in the Chicago area, with about 17,000 Comcast customers being affected. And though at first it sounds a bit like a schoolyard tussle, AT&T's lack of response has led Comcast to seek a restraining order from a court in Illinois.

While AT&T uses twisted pair cable to get to your front door, and Comcast uses coax, once they're inside, the signals share cabling. This means if you use U-Verse TV and Comcast broadband, and "feedback" from the U-Verse system spills upstream, it can affect the service of everyone connected to the same Comcast node. Comcast alleges that poor installation by U-Verse engineers is letting these signals leak via poor filters or systems using similar frequencies, and that AT&T has not motivated itself to fix the problem.

Unsurprisingly, AT&T is highly skeptical that U-Verse is the source of the issue. This is AT&T's position on the case: the "suit lacks merit," said a spokesperson. It's a bit of dirty work to try to keep them out of the Illinois cable TV market and AT&T will keep trying "to bring Illinois consumers a new choice for video services as we have in other states and will oppose Comcast's efforts to thwart that."

Comcast, however, is taking a holier-than-thou attitude: "AT&T should act like a good corporate citizen and work with Comcast to resolve this privately." Because Comcast supposedly behaves like that themselves, yes? [Arstechnica]